Aligner material, cleanliness, and quality detection via aligner case

ABSTRACT

Embedded sensors and onboard or off-board processing in an aligner case can detect aligner material and/or quality. Material detection can be used for counterfeit detection, or to trigger material specific events. Quality detection can include detection of common aligner failures or defects. A case for a dental appliance may include a tray for supporting the dental appliance, a cover coupled to the tray, and at least one sensor to detect a deformation of the dental appliance. A case for a dental appliance may include a tray for housing the dental appliance, a cover coupled to the tray, and at least one sensor configured to detect a change in material of the dental appliance.

REFERENCE TO EARLIER FILED APPLICATION

This application claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 62/859,893, filed Jun. 11, 2019, andtitled “ALIGNER MATERIAL AND QUALITY DETECTION VIA ALIGNER CASE,” whichis incorporated, in its entirety, by this reference.

BACKGROUND

Some patients have teeth with malocclusions or less than idealaesthetics, and it can be beneficial to move a patient's teeth toward adesired arrangement in order to correct malocclusions and/or improveaesthetics. To achieve these objectives, orthodontic and dentalappliances such as braces, shell aligners, and the like can be appliedto the patient's teeth. An appliance can be configured to exert force onone or more teeth in order to effect desired teeth movements accordingto stages of a treatment plan. In some instances, a treatment plan withdifferent stages of treatment may be generated by a treatmentprofessional (local, remote, etc.) and/or automated system. Thetreatment plan may prescribe appliance(s) for each stage of thetreatment to the patient. The patient can be asked to wear an appliancefor each stage of the treatment, and each appliance can be worn for anamount of time prior to switching to the next appliance for the nextstage. Each stage may move the teeth progressively towards a desiredlocation in accordance with the treatment plan. However, in someinstances one or more teeth may move more slowly than would be ideal.This can result in increased force to the one or more teeth anddeformation of the appliance in some instances.

During treatment with patient-removeable appliances, a treatmentprofessional may rely on a patient to comply with the prescribedappliance usage. A dental appliance may undergo degradations of qualityover time as the patient uses the appliance. For example, the dentalappliance may undergo failures or defects such as warpage, weakening,undesirable deformation, poor edge quality, discoloration, breakage,cracks, etc. Discovering such defects earlier during the treatment maybe beneficial to improve outcomes and mitigate delays in the treatmentprocess. However, in some instances, the patient may only visit atreatment professional occasionally, such as when specific stages ormilestones are reached or when the treatment is not proceeding accordingto plan. This can result in deviations from the treatment plan andappliance defects being detected somewhat later than would be ideal.

Prior methods and apparatus for monitoring dental appliance quality maybe inadequate in at least some instances. A treatment professional mayinspect an appliance occasionally, and patients may not be well-suitedto inspect dental appliances for warpage, undesirable deformation,weakening, etc. Issues which may have been detectable earlier may not benoticed until a patient complains, a treatment stage is not achieved, ora treatment professional inspects the appliance. By that time, theissues may have affected the patient's treatment. For example, one ormore of the patient's teeth may not have moved enough or may have movedtoo far which may ultimately cause delays the patient's treatment, orcall for a second (e.g., supplemental) treatment plan. While it may behelpful to monitor appliance quality, existing systems make it difficultto do so.

SUMMARY

Described herein are apparatuses and methods for monitoring a dentalappliance, including, but not limited to monitoring one or morequalities of the dental appliance. A case for the dental appliance maybe configured to monitor the dental appliance. The case may include oneor more sensors configured to obtain sensor data which may be analyzedto determine changes in quality of the dental appliance. The case mayinclude and/or be coupled to one or more processors coupled to thesensors and configured to process the sensor data in order to determinequality changes. Advantageously, the systems, methods, and devicesherein may provide feasible increased monitoring frequency of the dentalappliance to provide timely detection of quality issues. In addition,the increased monitoring may not be disruptive to the patient's usage ofthe dental appliance.

According to some embodiments, a case for a dental appliance may includea tray for supporting the dental appliance, a cover coupled to the tray,and at least one sensor to detect a deformation of the dental appliance.

In some embodiments, the at least one sensor may be configured to detectthe deformation based on tracking contact points of the dental appliancewith the at least one sensor.

In some embodiments, the at least one sensor may include a contactsensor on the tray to track relative positions of a plurality of contactpoints between the dental appliance and the contact sensor over time todetect the deformation. The deformation may be detected based on changesin the relative positions of the plurality of contact points. Thedeformation may be detected based on changes in a number of theplurality of contact points. The case may further include anaccelerometer for determining an orientation of the tray. The relativepositions of the plurality of contact points may be tracked based on theorientation. The case plurality of contact points may not be trackedwhen the tray has a tilted orientation.

In some embodiments, the case may further include a pressure sensor. Thepressure sensor may be configured to detect whether the dental applianceis on the tray.

In some embodiments, the at least one sensor may include a digitizerplatform. The digitizer platform may include a capacitive sensor todetect each of the plurality contact points and a corresponding locationof each of the contact points on the tray. The digitizer platform mayinclude an array of electrodes to detect locations of the plurality ofcontact points based on an electrical current between the array ofelectrodes and the plurality of contact points. The at least one sensormay include a conductive sensor configured to detect a plurality ofparallel conductive traces on the dental appliance. The digitizerplatform may include a digitizer coupled to processor to determinecorresponding locations of the plurality of contact points on the tray.The digitizer platform may be configured to detect locations of aplurality of contact points of a polymeric shell appliance. Thedigitizer platform may be configured to detect locations of each of theplurality of contact points with a spatial resolution finer than about 1mm.

In some embodiments, the at least one sensor may be configured to detectthe deformation based on tracking three-dimensional (3D) points of thedental appliance. The at least one sensor may include an optical sensor.The at least one sensor may include a camera to generate an image of theappliance on the tray and detect the deformation based on the image. Thecase may further include a light emitter. The optical sensor may beconfigured to detect a plurality of reflective markers on the dentalappliance. The at least one sensor may include a magnetic sensorconfigured to detect a plurality of magnets on the dental appliance.

In some embodiments, the case may further include a tag reader foridentifying the dental appliance. The tag reader may include one or moreof a QR code reader, a bar code reader, or an RFID scanner.

In some embodiments, the case may be operatively coupled to a processorconfigured to determine a treatment modification based on thedeformation.

In some embodiments, the case may further include a processoroperatively coupled to the at least one sensor to determine a firstshape of the appliance at a first time and a second shape of theappliance at a second time and to detect the deformation based on adifference between the first shape and the second shape. The processormay include one or more of a processor supported with the tray or aremote server. The processor may include instructions to detectdeformation of the appliance in response to a difference in relativelocations of a plurality of contact points. The first shape may includea first number of contact points and a second shape may include a secondnumber of contact points. The processor may include instructions todetect deformation of the appliance in response to a difference betweenthe first number of contact points and the second number of contactpoints. The processor may include instructions to determine anorientation of the appliance. The orientation may include a firstorientation corresponding to an occlusal side of the appliancecontacting the tray and a second orientation corresponding to a gingivalside of the appliance contacting the tray. The processor may includeinstructions to determine a plurality of shapes of the appliance over aplurality of days. The processor may be configured to detect deformationof the appliance.

According to some embodiments, a case for a dental appliance may includea tray for housing the dental appliance, a cover coupled to the tray,and at least one sensor configured to detect a change in material of thedental appliance.

In some embodiments, the at least one sensor may include an opticalsensor. The optical sensor may be configured to detect the change inmaterial based on reflectivity. The optical sensor may be configured todetect the change in material based on light scattering. The opticalsensor may be configured to detect the change in material based oncolor. The optical sensor may be configured to detect the change inmaterial based on detecting a color change of an indicator on the dentalappliance.

In some embodiments, the at least one sensor may include a capacitivesensor configured to detect a dielectric property of the dentalappliance.

In some embodiments, the case may further include a tag reader foridentifying the dental appliance. The tag reader may include a QR codereader. The tag reader may include an RFID scanner.

In some embodiments, the case may further include a processoroperatively coupled to the at least one sensor to determine a firstmaterial property of the appliance at a first time and a second materialproperty of the appliance at a second time and to detect the change inthe material property based on a difference between the first materialproperty and the second material property. The processor may include oneor more of a processor supported with the tray or a remote server. Theprocessor may include instructions to measure the material property ofthe appliance over a plurality of days. The processor may be configuredto determine the difference in the material property based on changesover the plurality of days.

INCORPORATION BY REFERENCE

All patents, applications, and publications referred to and identifiedherein are hereby incorporated by reference in their entirety, and shallbe considered fully incorporated by reference even though referred toelsewhere in the application.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the features, advantages and principles of thepresent disclosure will be obtained by reference to the followingdetailed description that sets forth illustrative embodiments, and theaccompanying drawings of which:

FIG. 1 shows, a dental appliance, in accordance with some embodiments;

FIG. 2 shows the cross-section of the dental appliance from FIG. 1 , inaccordance with some embodiments;

FIGS. 3A to 3B show a case for use with a dental appliance, inaccordance with some embodiments;

FIGS. 4A to 4D show a definition of a contact signature, in accordancewith some embodiments;

FIGS. 5A to 5C show a change over time in a contact signature, inaccordance with some embodiments;

FIGS. 6A to 6B show detection of a case orientation, in accordance withsome embodiments;

FIGS. 7A to 7C show tracking a 3D signature over time, in accordancewith some embodiments;

FIG. 8 shows magnetic sensors in accordance with some embodiments;

FIG. 9 shows a flowchart of a method in accordance with someembodiments;

FIGS. 10A to 10B show systems for observing changes in dental appliancestrain using birefringence, in accordance with embodiments;

FIG. 10C shows an example image of a birefringence pattern observedusing the techniques described herein, in accordance with someembodiments;

FIG. 10D shows a system for the observation of birefringence patterns inbuccal (or outer) and lingual (or inner) sidewalls of the dentalappliance in accordance with some embodiments; and

FIG. 11 shows a simplified block diagram of a data processing system.

DETAILED DESCRIPTION

The following detailed description and provides a better understandingof the features and advantages of the inventions described in thepresent disclosure in accordance with the embodiments disclosed herein.Although the detailed description includes many specific embodiments,these are provided by way of example only and should not be construed aslimiting the scope of the inventions disclosed herein. The methods,apparatus, dental appliances, and cases disclosed herein may be wellsuited for combination with many dental appliances and applications,such as an aligner for aligning a plurality of teeth, a retainer, apalatal expander, a bracket for placing attachments on a plurality ofteeth, an attachment for coupling to teeth, a nightguard, a functionalappliance, and other oral appliances. The presently disclosed methods,apparatus and appliances are well suited for monitoring (aka tracking) aquality of a dental appliance using one or more sensors embedded,attached, and/or coupled to a case for the dental appliance. A qualityof a dental appliance, as used herein, may include features and/orcharacteristics that define the dental appliance and/or allow the dentalappliance to perform according to its intended purpose. For aligners andretainers, the quality of a dental appliance may be based on physicaland/or geometrical properties, such as the extent the geometry of analigner or retainer deviates from its intended shape. The quality of adental appliance may be based on various factors, such as the extent thedental appliance exhibits deformation, warpage, or changes in materialdue to various factors, such as patient usage, factors related tomanufacturing, factors related to shipping, factors due to theenvironment in which the dental appliance is used, etc. The methods andapparatus disclosed herein are well suited for combination with variousdental appliances, such as aligners, including aligners commerciallyavailable from Align Technology, Inc., orthodontic retainers, and otherorthodontic appliances.

FIG. 1 illustrates an exemplary dental appliance 106 and jaw 104including a patient's teeth. FIG. 2 illustrates dental appliancecross-section 118 of the dental appliance 106 as taken along line 1B-1Bof FIG. 1 . The dental appliance 106 may be sized and shaped to fit overand resiliently reposition a plurality of teeth present in an upper orlower jaw. The dental appliance 106 may comprise a polymeric shellappliance having a thickness suitable for repositioning a plurality ofteeth. In some embodiments, the polymeric shell thickness may be no morethan about 2 millimeters, and, in some embodiments, the polymeric shellmay thickness may be with a range from about 0.2 millimeter to about 2millimeters, 0.4 mm to about 1.6 mm, 0.6 mm to about 1.4 mm, 0.8 mm toabout 1.2 mm, etc. The polymeric shell may comprise a plurality oflayers. As illustrated, the dental appliance 106 has a generallyU-shaped cross-section 118 to form one or more teeth receiving cavities109 shaped to receive and resiliently reposition one or more teeth of apatient, e.g., one or more teeth of the jaw 104. The dental appliance106 may comprise a thickness extending between an interior surface 107shaped to receive a tooth and the exterior surface 108 facing away fromthe tooth. In some embodiments, the exterior surface 108 comprises anocclusal surface 105 to engage an opposing appliance or opposing teethon an opposite side of the mouth. The occlusal surface 105 of appliance106 may extend along an occlusal plane 132. The methods and apparatusdisclosed herein may be used to fabricate the dental appliance 106 withvarious additive manufacturing and/or thermoforming techniques.

Although the cross-section shown in FIG. 2 shows a portion of theappliance extending across the tooth, in some embodiments, the applianceextends between teeth. The dimensions of the cross-section of theappliance can vary in accordance with the shape of patient's teeth. Forexample, an exterior surface of the appliance may protrude outwardlynear a midline of a tooth, and intrude slightly at mesial locations neara space between teeth. The methods, apparatus and appliances disclosedherein are well suited for addressing variations in geometry of apatient's dentition.

Although the embodiment of FIG. 1 illustrates a dental appliance in theform of an aligner, other types of dental appliances are suitable foruse. For example, dental appliance 106 may comprise a retainer, apalatal expander, a bracket for placing attachments on a plurality ofteeth, an attachment for coupling to teeth, a nightguard, a functionalappliance, or a directly fabricated aligner thermoforming mold.

FIGS. 3A-3B illustrate an exemplary case for housing a dental appliancewhich may detect a quality of the dental appliance. A case 310 mayinclude a cover 312 and a tray 314. The tray 314 may hold a digitizerplatform 316 which may be positioned on a base or floor of the tray 314.As will be discussed further below, the digitizer platform 316 may trackquality of the dental appliance 106. Although not visible in FIG. 3A,the case 310 may include sensors 318, such as an optical sensor, acamera, a magnetic sensor, a Hall effect sensor, a tag reader, a QR codereader, a bar code reader, and/or an RFID scanner. The sensors 318 maybe coupled to and/or embedded in and/or around the case 310, such as inthe cover 312, the tray 314, and/or the digitizer platform 316. The case310 may include a processor, memory, and/or other components of acomputer system coupled to the digitizer platform 316 and the sensors318, and may further be coupled to a computing device, such as a remoteserver, smartphone, etc., through wired and/or wireless connections. Anexample of the processor, memory, and/or other components may be foundin FIG. 11 .

In addition, although quality detection of a single dental appliance isdiscussed herein, multiple dental appliances may be housed and/ordetected within a container, such as case 310 holding multiple dentalappliances 106 in FIG. 3B which may correspond to the patient's upperand lower jaws.

Dental appliances may exhibit warpage over time. As the dental appliance106 is used, various forces may act on and/or against surfaces of thedental appliance 106. For example, physical resistance from teeth to beshaped, temperature fluctuations during storage, and/or other forces maycause degradation or other changes to a quality of the dental appliance106. Thus, a shape of the dental appliance 106 may be tracked.Deformations to the shape may be detected by determining a differencebetween a first shape at a first time compared to a second shape at asecond time. For instance, the shapes may be detected over multiple daysin order to detect deformations. Various other attributes, such asmaterial quality, cleanliness, shape, etc. may also be detected by thesensors 318 of the case 310.

The digitizer platform 316 may detect a shape of the dental appliance106. For instance, contact points of the dental appliance 106 against aflat, detection surface of the digitizer platform 316 may establish acontact signature of the dental appliance 106. “Contact points,” as usedherein, may include a set of locations at which the dental appliance 106physically touches the digitizer platform 316. The contact points maycomprise a continuous contact curve along which the dental appliance 106contacts the digitizer platform 316. In some embodiments, the contactpoints may comprise a discrete set of points disconnected from oneanother, but when evaluated, can be used to construct a pattern ofcontact by the dental appliance 106 against the digital platform 316. Asnoted herein, the pattern of contact may be used to infer a contactcurve, e.g., a one-dimensional curve formed by interpolating locationsof contact points based on one or more properties of the dentalappliance 106. A “contact signature,” as used herein, may include a setof contact points and/or a contact curve that is consistent withphysical properties of the dental appliance 106. A contact signature maybe associated with (e.g., unique to) the geometry of the dentalappliance 106. In some embodiments, a contact signature may comprise aplanar contact signature, e.g., a two-dimensional region formed from aset of points and/or curves that is consistent with thephysical/geometrical properties of the dental appliance 106.

The digitizer platform 316 may comprise a touch sensor such as acapacitive sensor and/or other contact sensor capable of detectingmultiple planar contact points. The digitizer platform 316 may beconfigured to detect contact points from the material of the dentalappliance 106, such as a polymeric shell appliance. The contact pointsmay correspond to the lowest points on teeth, such as the centers of thecrowns. The distances between center points may be, for instance 4 mm to8 mm for molars, 3 mm to 6 mm, etc. The digitizer platform 316 maytherefore be configured to detect locations of the contact points with asufficient spatial resolution that may be finer than, for example, about1 mm or less. In some implementations, the digitizer platform 316 mayinclude a set (e.g., an array) of electrodes which may detect locationsof the contact points based on an electrical current between theelectrodes and the contact points. For instance, the digitizer platform316 may include a conductive sensor configured to detect patterns ofconductive traces on the dental appliance 106. The conductive traces maybe, for example, small beads which may be detected to determinelocations of the conductive traces. In some embodiments, the patterns ofconductive traces comprise parallel conductive traces.

FIG. 4A illustrates the dental appliance 106 resting on the digitizerplatform 316. The dental appliance 106 may not sit flush against thedigitizer platform 316 due to the ridges, valleys, protrusions, and/orother geometrical properties in the shape of the dental appliance 106.These various attributes of the dental appliance 106 may contact thedigitizer platform 316 at contact points 426, that in turn may bedetected by the digitizer platform 316. These contact points 426 maydefine a contact signature of the dental appliance 106. Over time, asthe dental appliance 106 exhibits warpage, the contact points 426 mayshift relative to each other. Thus, tracking the contact signature overtime may reveal deformations to the dental appliance 106.

In some embodiments, the contact points 426 may be detected and/orrepresented by one or more coordinate systems. As an example, thecontact points 426 may be detected and/or represented by Cartesiancoordinates, as illustrated in FIG. 4B. For example, each contact point426 may have its own (x, y) coordinates. A contact signature 428 maytherefore be represented, in a simplistic model, by a collection ofcoordinates. To facilitate comparison between various iterations ofcontact signatures 428, the contact points 426 may be further organizedinto a specific order. The contact points 426 may generally fit along acurve 427. The curve 427 may correspond to a general U-shape of thedental appliance 106, although in other implementations the curve 427may comprise other shapes. Thus, the contact points 426 may be orderedalong the U-shape. For instance, the contact point 426 at the top leftof the U-shape may be p1, the next nearest contact point 426 along theU-shape may be p2, etc. until a last point pn. Using regression analysisand/or other similar curve recognition schemes, the points may beidentified (e.g., p1, p2, . . . pn). The regression analysis may furtheraccount for variations of the orientation of the U-shape, for instanceif the contact points 426 followed an upside U-shape, such that the samepoint along the same relative location along the U-shape may besimilarly identified. A subsequently detected contact signature 428having a different number of points may indicate a deformation.

The digitizer platform 316 may detect the contact points 426 based oncoordinates relative to the digitizer platform 316. Thus, if the dentalappliance 106 is not placed in the exact same location with respect tothe digitizer platform 316, the coordinates for the contact points 426may differ, even if the shape of the dental appliance 106 remainsunchanged. For instance, FIG. 4C illustrates the same contact signature428 as shown in FIG. 4B shifted with respect to the coordinate system ofthe digitizer platform 316. As seen in FIG. 3B, the size of the tray 314may allow the dental appliance 106 to be placed in various orientationsand/or locations on top of the digitizer platform 316. However, a strictcoordinate comparison between corresponding points (e.g., p1 of firstand second contact signature reading) of contact signatures 428 mayreveal shifted coordinates. It may be impractical to require the dentalappliance 106 to be consistently placed in the same location on thedigitizer platform 316. Therefore, tracking the relative positionsbetween the contact points 426 may be allow the tracking to beposition-independent with respect to the case 310. The dental appliance106 may be placed anywhere on the digitizer platform 316 as long as thedental appliance 106 is fully within the case 310.

As illustrated in FIG. 4D, the contact signature 428 may be representedas a set of vectors between the contact points 426. Following thecontact point organization along the curve 427 as discussed above,vector p^(1/2) may be a vector from point p1 to point p2, vector p^(2/3)may be a vector from point p2 to point p3, etc. In FIG. 4C, thecoordinates of the points p1 . . . pn may have shifted (e.g., due toplacement on a different location on the digitizer platform 316), butthe locations of the contact points 426 with respect to each other, asrepresented by vectors p^(1/2) . . . p^(n−1/n), may be the same,indicating the same contact signature 428.

FIGS. 5A-5C illustrate how contact signature 528 may be tracked overtime. In FIG. 5A, at a first time, contact points 526 of contactsignature 528 may have specific positions with respect to each other. InFIG. 5B, at a second time after the first time, one point (e.g., theupper right point) may have shifted with respect to other points (e.g.,the upper left point and the middle point) as compared to FIG. 5A. InFIG. 5C, at a third time after the second time, additional points (e.g.,the upper left point and the middle point) may have shifted with respectto another point (e.g., the upper right point) as compared to FIG. 5B.Thus, changes between each contact signature reading (e.g., between FIG.5A and FIG. 5B and between FIG. 5B and FIG. 5C) may be tracked as wellas changes between non-consecutive readings (e.g., between FIG. 5A andFIG. 5C).

The contact signature 528 may correspond to the shape of the dentalappliance 106 in that changes to the shape may be reflected in changesto the contact signature 528. For example, as illustrated in FIGS.5A-5C, changes to the relative locations of the contact points 526 mayindicate changes to the shape such that a processor coupled to thedigitizer platform 316 may detect a deformation when differences in therelative locations of the contact points 526 are detected. Otherchanges, such as a difference between a first number of contact pointsand a second number of contact points, may also indicate a deformation.

To further ensure consistent and accurate readings over time, the case310 may include sensors 318 which may detect suboptimal conditions fordetecting contact signatures. For instance, the sensors 318 may includean accelerometer and/or other sensors capable of detecting anorientation of the case 310. If the case 310 is tilted during a contactsignature reading, the dental appliance 106 may shift such that certaincontact points may not be accurately detected by the digitizer platform.In a worst-case scenario, the case 310 may be orientated such that thedental appliance does not contact the digitizer platform, such as if thecase 310 was on its side or upside down.

FIGS. 6A-6B illustrate an orientation 629 of the case 310. Theorientation 629 may indicate how parallel the ground the case 310 isorientated. In other words, the orientation 629 may indicate howperpendicular a plane 311, corresponding to a level plane of the case310 and the digitizer platform 316, is with respect to a downward orgravitational direction. In FIG. 6A, the orientation 629 may beconsidered level. For instance, the orientation 629 may be within athreshold distance from a level orientation indicating that the plane311 is coplanar with the ground plane. Thus, in FIG. 6A a relativelyaccurate contact signature reading may be obtained.

In FIG. 6B, the orientation 629 may not be level. For example, theorientation 629 may be outside the threshold distance from the levelorientation. When the case 310 is tilted as such, an accurate contactsignature reading may not be obtained. In some implementations, thedigitizer platform 316 may not record a contact signature when theorientation 629 is not considered level. For instance, the contactpoints may not be tracked when the case 310 has a tilted orientation. Insome implementations, the user may be notified that the case 310 is notlevel, for instance by a visual indicator on the case 310 or through anotification via a connected computing device. In certainimplementations, the digitizer platform 316 may account for theorientation 629. For instance, the contact points may be further trackedbased on the orientation 629. The contact signature may be estimated asif the case 310 were level. In certain implementations, the case 310 mayinclude, for instance in the cover 312, a mechanical device for ensuringconsistent contact between the dental appliance 106 and the digitizerplatform 316.

The digitizer platform 316 and/or sensors 318 may further include apressure sensor. The pressure sensor may detect whether the dentalappliance 106 is on the tray 314. For example, the pressure sensor maydetect whether an object has been placed on the tray 314 beforeactivating the capacitive sensor of the digitizer platform 316. Thepressure sensor may determine whether the dental appliance 106 oranother foreign object has been placed on the tray 314, such as bydetecting an expected weight and/or surface area of contact. In someimplementations, the digitizer platform 316 may make a contact signaturereading when the pressure sensor indicates the presence of an object andthe accelerometer detects that the case 310 is level.

The case 310 may be configured to identify the dental appliance 106, forinstance to distinguish between different dental appliances. The sensors318 may include a tag reader for identifying the dental appliance 106.For example, the tag reader may be a QR code reader, a bar code reader,an RFID scanner, etc. for detecting an identifier (e.g., a QR code, abar code, an RFID tag, etc.) on the dental appliance 106.

Identifying the dental appliance 106 may further include identifying anorientation of the dental appliance 106. For instance, the case 310and/or the processor coupled thereto may recognize at least a firstorientation of the dental appliance 106 corresponding to an occlusalside of the dental appliance 106 contacting the tray 314 and at least asecond orientation corresponding to a gingival side of the dentalappliance 106 contacting the tray 314. In certain implementations, thefirst and second orientations may be detected based on distinct contactsignatures between the two orientations. For example, the contactsignatures of the first and second orientations may differ beyond athreshold indicating possible deformations, such as differences in anumber of contact points not normally expected as a result of warpage.In other implementations, the identifier tag may include orientationinformation or may otherwise be sensitive to orientation, such as anoptical tag indicating a direction. In yet other implementations, thecase 310 may be capable of detecting a three-dimensional (3D) shape ofthe dental appliance 106, as will be explained further below. In theseimplementations, the case 310 may recognize the orientation based on the3D shape.

The sensors 318 of the case 310 may include sensors which may track 3Dpoints on the dental appliance 106. In FIGS. 7A and 7B, the sensors 318may be placed in the case 310 to be around the dental appliance 106 whenthe dental appliance 106 is within the case 310. The 3D points may beidentified by markers 727. The markers 717 may be active and/or passivecomponents. Active components may include, for instance, sensors whichmay detect and broadcast its own location. Passive components mayinclude optical markers, magnets, and/or other components which may beactivated or actively sensed when within the case 310. For example, thesensors 318 may include optical sensors, such as a camera which maygenerate an image of the dental appliance 106 on the tray 314 in orderto detect deformations based on the image. The markers 727 may bereflective markers to be more consistently detected by optical sensors.In such implementations, the case 310 may include a light emitter toreflect light off the markers 727 and be detected by the sensors 318.The images may be analyzed, using image analysis, to determine spatiallocations of the markers 727. For example, color intensities,differences in brightness, etc. may be used to determine deformation,strain, depth and spatial locations. The sensors 318 may includeadditional sensors, such as optical, laser, IR, and/or radio sensors, toassist in depth perception and other spatial awareness detection. Theimage analysis may further be used to identify the dental appliance 106as well as the orientation of the dental appliance 106.

Similar to the planar contact signature described above, a 3D signaturemay be defined by relative locations between the markers 727. Forexample, in FIG. 7B, 3D distance vectors d1, d2, and d3 between themarkers 727 may be determined to define the 3D signature. At asubsequent 3D signature reading, the marker 731 a may have shifted to amarker 732 b. The shift may be detected based on changes to the distancevectors. For example, d1 may have changed by a Δd1 and d2 may havechanged by a Δd2. The deltas may be indicative of one or moredeformations in the dental appliance 106.

FIG. 7C illustrates a graphical way of tracking changes to the 3Dsignature. The markers 727 may be monitored over time for changes.Specific changes, such as changes in particular magnitudes and/orparticular directions, particular combinations of changes, etc., may beindicative of particular deformations. For instance, particulardeformations may correspond to particular tooth locations. In someimplementations, the case 310 and/or the processor coupled thereto maybe configured to determine a treatment modification based on detecteddeformations. For example, during treatment, one or more particulardeformations (e.g., deformations with respect to specific toothlocations) may be expected at particular times (e.g., a specified numberand/or range of days from a start of the treatment) for successfultreatment. Deviations from the particular deformations at the expectedparticular times may indicate that the treatment may need to bemodified.

The expected deformations may be tracked based on expected locations ofthe markers 727 and/or contact points 426, 526. For example, thetreatment may expect the markers 727 and/or contact points 426, 526 tohave specific relative locations at particular times during thetreatment. If the specific relative locations, within a tolerancethreshold, are not detected at the expected time, the correspondingtooth may not have moved as expected for the treatment. The patientand/or treatment professional may be alerted based on a type and/ormagnitude of deviation from the expected deformation.

The sensors 318 may include proximity sensors for detecting proximitiesof the markers 727. In FIG. 8 , the sensors 318 may include a magneticsensor, such as a Hall effect sensor. The markers 827 may be magnets ormagnetic markers. The sensors 318 may detect the 3D locations of themarkers 827 with respect to the sensors 318. The sensors 318 may detectthe distances based on a magnitude and orientation of a magnetic fieldof the marker 827. For instance, sensor s1 may detect a distance p1 ofthe marker 827 from the sensor s1. Similarly, sensor s2 may detect adistance p2 of the marker 827 from the sensor s2. Based on p1, p2, andthe known locations of the sensors s1 and s2, the 3D location of themarker 827 may be determined. The relative locations between markers 827may then be determined for the 3D signature, and changes to the 3Dsignature may be tracked to detect deformations in the dental appliance106 as described herein.

In certain implementations, rather than tracking a plurality of points(e.g., the contact points 426, 526, and/or the markers 727), a singlepoint, such as a weighted midpoint of the markers and/or contact points,may be determined and tracked. Thus, changes to any of the points may bereflected in a change to the midpoint. The midpoint may be weightedbased on, for instance, a detected weight or mass of the dentalappliance.

Although the shape of the dental appliance 106 may be tracked based onspecific points (e.g., the contact points 426, 526 and/or the markers727), in certain implementations, granular changes to the shape may bedetected by tracking the overall shape of the dental appliance 106. Forexample, computer vision may be used with the image analysis describedherein to recognize the shape. Computer vision may be used to create a3D map of the dental appliance. The granularity of such detection may bebased on a number of 3D points detected.

The case 310 and/or the processor coupled thereto may also be configuredto detect changes to other qualities, such as one or more other materialproperties of the dental appliance 106, instead of and/or in addition toshape. The material property may include one or more of materialcomposition, hardness and/or resiliency, and other properties which mayindicate degradation of the dental appliance 106. The case 310, usingthe sensors 318, may detect a first material property at a first timeand a second material property at a second time and to determine achange based on a difference between the first material property and thesecond material property. The material property may be measured, forinstance, over multiple days. The material property may be a materialcomposition of the dental application 106. Alternatively, rather thanspecifically detecting a material composition, changes in the materialcomposition, such as changes from an initial reading, may be detected.Alternatively, sensor data from the sensors 318 may be correlated toknown properties of known materials. Changes to qualities of the dentalappliance 106 may be monitored, for instance, to provide feedback to thepatient and/or treatment professional and further provide alerts whenaction and/or modification to the treatment are needed.

The sensors 318 may include, for example, an optical sensor. Asdescribed herein, the optical sensor may be used to detect warpage suchas deformations. The optical sensor may also be configured to detectchanges to the material properties based on reflectivity. For example,the dental appliance 106 may be made of a specific known material whichmay be expected to exhibit a corresponding known reflectivity. The knownreflectivity may correspond to a predetermined value (such as anempirically determined value or other reference value) or may correspondto an initial measurement at the start of the treatment. Changes to thematerial property may be indicated by deviation of the measuredreflectivity beyond a reflectivity threshold. In some embodiments, thedeformation of and/or strain in the dental appliance 106 may be measuredusing birefringence, as discussed below with reference to FIGS. 10A to10D.

Alternatively and/or in addition to reflectivity, the optical sensor maybe configured to detect changes based on light scattering. Changes tothe material property may be indicated by a deviation of a measuredlight scattering beyond a scattering threshold from a referencescattering measurement. The reference scattering measurement may bebased on a predetermined value (such as an empirically determined valueor other reference value) or may correspond to an initial measurement atthe start of the treatment. For example, as the dental appliance 106wears down, its surface may deteriorate and change its light scatteringproperties.

The optical sensor may be configured to detect changes based on color.Changes to the material property may be indicated by a deviation of ameasured color beyond a color threshold from a reference color. Thereference color may be based on a predetermined value (such as anempirically determined value or other reference value) or may correspondto an initial measurement at the start of the treatment. For example, asthe dental appliance 106 wears down, the material may change in materialcomposition (e.g., absorb foreign materials and/or expel material) whichmay result in changes to its color.

The optical sensor may be configured to detect changes based ondetecting a color change of an indicator on the dental appliance 106.For example, a reactive indicator may change color in the presence ofcertain agents, which may further be indicative of a change to thematerial. For instance, one or more indicators may be configured toreact to specific compounds (e.g., chemical byproducts from materialdegradation and/or reactions to other materials, pH, etc.). Changes tothe material property may be indicated by the color change of theindicator beyond an indicator threshold from a reference indicatorcolor. The reference indicator color may be based on a predeterminedvalue (such as an empirically determined value or other reference value)or may correspond to an initial measurement at the start of thetreatment.

The sensors 318 may include a capacitive sensor configured to detect adielectric property of the dental appliance 106. Changes to the materialproperty may be indicated by a deviation of a measured dielectricproperty beyond a dielectric threshold from a reference dielectricproperty measurement. The reference dielectric property measurement maybe based on a predetermined value (such as an empirically determinedvalue or other reference value) or may correspond to an initialmeasurement at the start of the treatment.

FIGS. 10A to 10B depicts a system 1000 for observing birefringence in adental appliance 106 and the resulting observed birefringence pattern1050. Birefringence is an optical property of a material having arefractive index that depends on the polarization and propagationdirection of light passing though it. Polymer materials, such as thoseused in dental appliances may exhibit birefringence. The patterns andintensity of observed birefringence in a dental appliance may changebased on the strain within the dental appliance. The strain in appliancechanges the polymer structure, for example, by stretching or relaxingthe polymer chains that make up the material of the dental appliance. Byobserving these changes in the birefringence of a dental appliance adetermination may be made as to whether and appliance is overstrainedand should be replaced. Birefringence patterns may be observed byilluminating the dental appliance with white light, placing a polarizingfilter between the illumination source and the dental appliance, placinga second polarizing filter oriented 90° to the first polarizing filter,and observing the appliance through the second polarizing filter.

In FIG. 10A, the system 1000 includes a light source 1010, a firstpolarizing filter 1020, a dental appliance 1006, a second polarizingfilter 1030, and a sensor 1040 (e.g., an optical sensor, camera, etc.).The light source 1010 provides white light or other broad spectrumvisible light illumination projected towards the appliance. Theprojected light is polarized by the first polarizing filter 1020. Thepolarized light then passes through the dental appliance 106 where it isrefracted by the dental appliance. Light projected though the dentalappliance then passes through the second polarizing filter 1030. Thesecond polarizing filter 1030 is oriented 90° from the polarizing filter1020 such that the second polarizing filter 1030 polarizes lightorthogonally to the polarization of the first polarizing filter 1020.The birefringence pattern of the dental appliance 1006 may then beobserved or recorded by a sensor such as the camera 1040.

In some embodiments, the system 1000 may be implemented in an appliancecase such as appliance case 310. In such an embodiment, a light sourceand first polarizing filter may be integrated into one or the other of acover 312 and the tray 314 and the second polarizing filter may beincorporated in the other of the cover 312 and the tray 314. A sensor(e.g., camera, other optical sensor, etc.) may also be located in theother of the cover 312 in the tray 314. In some embodiments, the lightsource may be an ambient light source, such as lights in a room ornatural light. In such embodiments, the appliance case may be made fromclear, semitranslucent, or translucent material. In some embodiments thelight source may include backlighting structures such as LEDbacklighting or other light sources. In some embodiments, the lightsources may include light guides or light pipes formed in the cover ortray. As discussed above, the first polarizer 1020 and the secondpolarizer 1030 are oriented 90° with respect to each other. Such anarrangement of light source and sensor in opposite sides of the case 310may allow observation of birefringence patterns through the occlusalsurface of the appliance 106.

FIG. 10B shows a system 1000 for the observation of birefringencepatterns in buccal and lingual sidewalls of the dental appliance 106. InFIG. 10B, the light source 1010 and the first polarizer 1020 are locatedon a first side of a tooth receiving cavity of the dental appliance 106,for example a lingual side, while the second polarizer 1030 and thecamera 1040 are located on a second side of the tooth receiving cavityof the dental appliance 106, for example a buccal side. In such anarrangement, light from the light source 1010 is polarized at a firstangle by the first polarizer 1020 and then projected through theappliance, and then through the second polarizer 1030 that is oriented90° to the first polarizer 1020. The camera 1040 may observe thebirefringence pattern in the dental appliance 106 through the secondpolarizer 1030.

The arrangement shown in FIG. 10B may be implemented in a dentalappliance case, such as case 310 by placing the light source and firstpolarizer in a central location of the case. For example, in a locationsuch that when the dental appliance 106 is placed within the case, thelight source and polarizer are within the U of the U-shaped dentalappliance 106, such as between left and right molar tooth receivingcavities of the dental appliance 106. A second polarizer 1030 and one ormore cameras 1040 may be placed about the outside or sidewalls the case310. In some embodiments, the location of the light source and firstpolarizer may be about the outside or sidewalls of the case 310 whilethe second polarizer and sensor or camera 1040 is located within the Uof the U-shaped dental appliance 106.

In some embodiments the light source may be a polarized light source andthe first polarizer 1020 may be omitted. Similarly, the second polarizer1030 may be integrated into the sensor or camera 1040.

In some embodiments, it may be desirable to know the location of thebirefringence pattern and associated strain in the appliance 106. Forexample, the systems and methods described herein for determining theorientation of the dental appliance 106 within the case 310 may be usedin combination with a known or determined position of the camera 1040 inorder to determine the portion or portions of the dental appliance 106in an image captured by the camera 1040. In some embodiments, othermethods may be used to determine the portion or portions of the dentalappliance 106 and the captured image along with the location of thebirefringence patterns observed in the dental appliance 106. Forexample, edge detection, computer vision, and/or machine learningtechniques may be used to determine the portion or portions of theappliance within the field of view of the camera and the locations ofthe birefringence patterns in the dental appliance 106.

FIG. 10C shows an example image of a birefringence pattern observedusing the techniques described herein. The birefringence pattern 1050 isobservable as changes in gradients and intensity of color in thealigner. Observation of changes in birefringence patterns over time mayshow locations of increased strain within the aligner, for example, atinter-proximal areas between adjacent tooth receiving cavities or onsidewalls or occlusal surfaces of the cavities. In some embodiments,increased strain may be observed by changes in the birefringence patternnear attachment receiving cavities within the appliance. Changed strainmay indicate a change in quality of the dental appliance, such adecrease in the dental appliance's effectiveness in moving teeth, andmay result in changes to the patient's treatment plan, for examplechanging aligners early, among other changes to the treatment plan.

FIG. 9 illustrates a flowchart of an exemplary method 900 for detectinga quality change of a dental appliance in a case. As described herein,the quality may correspond to one or more of a shape (e.g., via contactsignature and/or 3D signature), material composition, material property,etc. and other detectable characteristics (e.g., reflectivity,dielectric property, etc.) which may correspond to quality issues.Common dental appliance failures and/or defects, such as warpage, pooredge quality, discoloration, breakage, cracks, etc., may be detected.

At 910, a dental appliance is detected inside a case. The case 310 maydetect the presence of the dental appliance 106 via the digitizerplatform 316 and/or the sensors 318 in a variety of ways, as discussedabove. For instance, the sensors 318 may include a pressure sensor fordetecting the dental appliance 106 pressing against the tray 314. Thesensors 318 may include an optical sensor for detecting the dentalappliance 106 and/or the markers 727. In some implementations, detectingthe dental appliance 106 may include identifying the dental appliance106, for instance through scanning a tag and/or computer vision. Forexample, the patient may have different dental appliances for thepatient's upper and lower jaws. Both dental appliances 106 may bepresent in the case 310 (see, e.g., FIG. 3B), which may both beidentified and effectively tracked simultaneously. Alternatively, otherpatients may use the case 310 for their dental appliances. However, incertain implementations, the case 310 may be linked to one or moreparticular dental appliances 106 such that unrecognized or unauthorizeddental appliances may be ignored. For instance, counterfeit dentalappliances may be identified. Alternatively, a type of dental appliancemay trigger specific events. For instance detecting an aligner maytrigger one type of action (e.g., a particular detection scheme) whereasdetecting a retainer may trigger a different type of action (e.g., adifferent detection scheme). In some implementations, identifying thedental appliance 106 may further include identifying the orientation ofthe dental appliance 106 within the case 310. The orientation of thedental appliance 106 may factor into the quality determinationsdescribed herein.

At 920, a quality of the dental appliance may be determined. Forexample, the case 310 and/or the processor connected thereto may detectthe shape using the digitizer platform 316 and/or sensors 318 asdescribed herein. In some implementations, a combination of detectionschemes may be used for the dental appliance 106. For instance, alldetection schemes (e.g., contact signature, 3D signature, reflectivity,dielectric property, etc.) or a subset thereof may be applied. In someimplementations, a specific combination of detection schemes may beapplied to a specific dental appliance 106. For instance, contactsignature may be applied to the dental appliance 106 for the patient'supper jaw, and 3D signature may be applied to the dental appliance 106for the patient's lower jaw. In certain implementations, the detectionschemes may be exclusive to particular dental appliances which mayproduce more accurate measurements for each when multiple dentalappliances are detected. For example, contact signature may be appliedto the dental appliance 106 for the patient's upper jaw, and 3Dsignature may be applied to the dental appliance 106 for the patient'slower jaw, such that when both dental appliances 106 are detected withinthe case 310, both may be measured without interference with the other'smeasurement. In certain implementations, the detection schemes appliedmay be based on a number of dental appliances associated with and/ordetected within the case 310.

At 930, the determined quality may be compared against quality recordsfor the dental appliance. For the corresponding detection scheme, priordata may be stored, for example in a memory coupled to the case 310. Thememory may be located on or remotely connected to the case 310 and/orthe processor coupled thereto, using wired and/or wireless connections.The current measurements may be compared against the prior data fromprior measurements for the respective dental appliance. In someimplementations, the quality records may include and/or be reflected ofother collected data, such as data from other patients' dentalappliances. Such aggregate analysis may provide further insight and/orimprovement to detecting deviations. For instance, the variousthresholds described herein may be updated based on the aggregateanalysis. In addition, the current measurements may be added to thequality records.

At 940, a change to the quality of the dental appliance may be detectedbased on the comparison. As discussed herein, the quality may be trackedover time. Such monitoring may provide indications as to quality issues(e.g., degradation of the dental appliance). The monitoring may alsoidentify a stage of the treatment process. For instance, detecteddeformations may correspond to a specific stage or milestone of thetreatment. A progress of the treatment may be determined, for instancebased on a timing of when a milestone is reached compared to an expectedtiming. Other deviations may indicate issues to be addressed by thepatient and/or treatment professional. For example, certain deformationsmay correspond to the patient deviating from the treatment process.Other deformations may indicate a need for the treatment professional tomodify or customize the treatment, such as if a tooth has not moved asexpected.

Thus, the systems and methods described herein may provide tracking ofone or more qualities of dental appliances using the dental appliances'cases. When a patient stores his or her dental appliance in itscorresponding case, the case may measure one or more measurable aspectsusing sensors configured to detect these aspects of the dentalappliance. By tracking these measurements over time, quality issuesregarding the dental appliance may be detected. For example, expectedand/or unexpected warping may be detected, changes to the materialcomposition may be detected, etc. These changes may further beindicative of issues that may need to be addressed by the patient and/ora treatment professional.

FIG. 10D shows a system 1000 for the observation of birefringencepatterns in buccal (or outer) and lingual (or inner) sidewalls of thedental appliance 106. In FIG. 10D, the light source 1010 and the firstpolarizer 1020 are located on a first side of a tooth receiving cavityof the dental appliance 106, for example a buccal side outside the archof the dental appliance 106, while the second polarizer 1030 and thecamera 1040 are located within the tooth receiving cavity or cavities ofthe dental appliance 106. In such an arrangement, light from the lightsource 1010 is polarized at a first angle by the first polarizer 1020and then projected through a outer or facial or buccal sidewall of theappliance, and then through the second polarizer 1030 that is oriented90° to the first polarizer 1020. The camera 1040 may observe thebirefringence pattern in the dental appliance 106 through the secondpolarizer 1030.

In some embodiments, the light source 1010 and the first polarizer 1020are located on a first side of a tooth receiving cavity of the dentalappliance 106, for example a lingual side within the arch of the dentalappliance 106, while the second polarizer 1030 and the camera 1040 arelocated within the tooth receiving cavity or cavities of the dentalappliance 106. In such an arrangement, light from the light source 1010is polarized at a first angle by the first polarizer 1020 and thenprojected through an inner or lingual sidewall of the appliance, andthen through the second polarizer 1030 that is oriented 90° to the firstpolarizer 1020. The camera 1040 may observe the birefringence pattern inthe dental appliance 106 through the second polarizer 1030.

The arrangement shown in FIG. 10D may be implemented in a dentalappliance case, such as case 310 by placing the light source and firstpolarizer in the case such that when the dental appliance 106 is placedwithin the case, the light source and polarizer are within toothreceiving cavities of the dental appliance 106, such as between buccaland lingual sidewalls of the tooth receiving cavities. In someembodiments, the first polarizer and light source may be shaped along aU-shaped wall that follows the curve of the arch of the aligner 106. Asecond polarizer 1030 and one or more cameras 1040 may be placed aboutthe outside or sidewalls the case 310. In some embodiments, the locationof the light source and first polarizer may be about the outside orsidewalls of the case 310 while the second polarizer and sensor orcamera 1040 is located within tooth receiving cavities of the dentalappliance 106.

In some embodiments the light source may be a polarized light source andthe first polarizer 1020 may be omitted. Similarly, the second polarizer1030 may be integrated into the sensor or camera 1040.

FIG. 11 is a simplified block diagram of a data processing system 1100that may be used in executing methods and processes described herein.The data processing system 1100 typically includes at least oneprocessor 1102 that communicates with one or more peripheral devices viabus subsystem 1104. These peripheral devices may include a storagesubsystem 1106 (memory subsystem 1108 and file storage subsystem 1114),a set of user interface input and output devices 1118, and an interfaceto outside networks 1116. This interface is shown schematically as“Network Interface” block 1116, and is coupled to correspondinginterface devices in other data processing systems via communicationnetwork interface 1124. Data processing system 1100 can include, forexample, one or more computers, such as a personal computer,workstation, mainframe, laptop, and the like.

The user interface input devices 1118 are not limited to any particulardevice, and may include, for example, a keyboard, pointing device,mouse, scanner, interactive displays, touchpad, joysticks, etc.Similarly, various user interface output devices can be employed in asystem of the invention, and can include, for example, one or more of aprinter, display (e.g., visual, non-visual) system/subsystem,controller, projection device, audio output, and the like.

Storage subsystem 1106 maintains the basic required programming,including computer readable media having instructions (e.g., operatinginstructions, etc.), and data constructs. The program modules discussedherein are typically stored in storage subsystem 1106. Storage subsystem1106 typically includes memory subsystem 1108 and file storage subsystem1114. Memory subsystem 1108 typically includes a number of memories(e.g., RAM 1110, ROM 1112, etc.) including computer readable memory forstorage of fixed instructions, instructions and data during programexecution, basic input/output system, etc. File storage subsystem 1114provides persistent (non-volatile) storage for program and data filesand can include one or more removable or fixed drives or media, harddisk, floppy disk, CD-ROM, DVD, optical drives, and the like. One ormore of the storage systems, drives, etc may be located at a remotelocation, such coupled via a server on a network or via theinternet/World Wide Web. In this context, the term “bus subsystem” isused generically so as to include any mechanism for letting the variouscomponents and subsystems communicate with each other as intended andcan include a variety of suitable components/systems that would be knownor recognized as suitable for use therein. It will be recognized thatvarious components of the system can be, but need not necessarily be atthe same physical location, but could be connected via variouslocal-area or wide-area network media, transmission systems, etc.

As detailed above, the computing devices and systems described and/orillustrated herein broadly represent any type or form of computingdevice or system capable of executing computer-readable instructions,such as those contained within the modules described herein. In theirmost basic configuration, these computing device(s) may each comprise atleast one memory device and at least one physical processor.

The term “memory” or “memory device,” as used herein, generallyrepresents any type or form of volatile or non-volatile storage deviceor medium capable of storing data and/or computer-readable instructions.In one example, a memory device may store, load, and/or maintain one ormore of the modules described herein. Examples of memory devicescomprise, without limitation, Random Access Memory (RAM), Read OnlyMemory (ROM), flash memory, Hard Disk Drives (HDDs), Solid-State Drives(SSDs), optical disk drives, caches, variations or combinations of oneor more of the same, or any other suitable storage memory.

In addition, the term “processor” or “physical processor,” as usedherein, generally refers to any type or form of hardware-implementedprocessing unit capable of interpreting and/or executingcomputer-readable instructions. In one example, a physical processor mayaccess and/or modify one or more modules stored in the above-describedmemory device. Examples of physical processors comprise, withoutlimitation, microprocessors, microcontrollers, Central Processing Units(CPUs), Field-Programmable Gate Arrays (FPGAs) that implement softcoreprocessors, Application-Specific Integrated Circuits (ASICs), portionsof one or more of the same, variations or combinations of one or more ofthe same, or any other suitable physical processor.

Although illustrated as separate elements, the method steps describedand/or illustrated herein may represent portions of a singleapplication. In addition, in some embodiments one or more of these stepsmay represent or correspond to one or more software applications orprograms that, when executed by a computing device, may cause thecomputing device to perform one or more tasks, such as the method step.

In addition, one or more of the devices described herein may transformdata, physical devices, and/or representations of physical devices fromone form to another. For example, one or more of the devices recitedherein may receive image data of a sample to be transformed, transformthe image data, output a result of the transformation to determine a 3Dprocess, use the result of the transformation to perform the 3D process,and store the result of the transformation to produce an output image ofthe sample. Additionally or alternatively, one or more of the modulesrecited herein may transform a processor, volatile memory, non-volatilememory, and/or any other portion of a physical computing device from oneform of computing device to another form of computing device byexecuting on the computing device, storing data on the computing device,and/or otherwise interacting with the computing device.

The term “computer-readable medium,” as used herein, generally refers toany form of device, carrier, or medium capable of storing or carryingcomputer-readable instructions. Examples of computer-readable mediacomprise, without limitation, transmission-type media, such as carrierwaves, and non-transitory-type media, such as magnetic-storage media(e.g., hard disk drives, tape drives, and floppy disks), optical-storagemedia (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), andBLU-RAY disks), electronic-storage media (e.g., solid-state drives andflash media), and other distribution systems.

A person of ordinary skill in the art will recognize that any process ormethod disclosed herein can be modified in many ways. The processparameters and sequence of the steps described and/or illustrated hereinare given by way of example only and can be varied as desired. Forexample, while the steps illustrated and/or described herein may beshown or discussed in a particular order, these steps do not necessarilyneed to be performed in the order illustrated or discussed.

The various exemplary methods described and/or illustrated herein mayalso omit one or more of the steps described or illustrated herein orcomprise additional steps in addition to those disclosed. Further, astep of any method as disclosed herein can be combined with any one ormore steps of any other method as disclosed herein.

Unless otherwise noted, the terms “connected to” and “coupled to” (andtheir derivatives), as used in the specification and claims, are to beconstrued as permitting both direct and indirect (i.e., via otherelements or components) connection. In addition, the terms “a” or “an,”as used in the specification and claims, are to be construed as meaning“at least one of” Finally, for ease of use, the terms “including” and“having” (and their derivatives), as used in the specification andclaims, are interchangeable with and shall have the same meaning as theword “comprising.

The processor as disclosed herein can be configured with instructions toperform any one or more steps of any method as disclosed herein.

As used herein, the term “or” is used inclusively to refer items in thealternative and in combination.

As used herein, characters such as numerals refer to like elements.

Embodiments of the present disclosure have been shown and described asset forth herein and are provided by way of example only. One ofordinary skill in the art will recognize numerous adaptations, changes,variations and substitutions without departing from the scope of thepresent disclosure. Several alternatives and combinations of theembodiments disclosed herein may be utilized without departing from thescope of the present disclosure and the inventions disclosed herein.Therefore, the scope of the presently disclosed inventions shall bedefined solely by the scope of the appended claims and the equivalentsthereof.

What is claimed is:
 1. A case for a dental appliance, the casecomprising: a tray including a flat platform for supporting the dentalappliance directly thereon; a cover coupled to the tray; and at leastone contact sensor on the tray configured to detect positions of aplurality of contact points of the dental appliance between the dentalappliance and the tray over time, the contact sensor couplable inelectronic communication to a processor configured to determine adeformation of the dental appliance based on tracking a change inrelative positions of the plurality of contact points of the dentalappliance and the tray over time.
 2. The case of claim 1, wherein thedeformation is detected based on changes in a number of the plurality ofcontact points.
 3. The case of claim 1, further comprising anaccelerometer for determining an orientation of the tray, wherein therelative positions of the plurality of contact points is tracked basedon the orientation.
 4. The case of claim 3, wherein the plurality ofcontact points is not tracked when the tray has a tilted orientation. 5.The case of claim 1, wherein further comprising a pressure sensor. 6.The case of claim 5, wherein the pressure sensor is configured to detectwhether the dental appliance is on the tray.
 7. The case of claim 1,wherein the at least one sensor comprises a digitizer platform.
 8. Thecase of claim 7, wherein the digitizer platform comprises a capacitivesensor to detect each of the plurality contact points and acorresponding location of each of the contact points on the tray.
 9. Thecase of claim 8, wherein the digitizer platform comprises an array ofelectrodes to detect locations of the plurality of contact points basedon an electrical current between the array of electrodes and theplurality of contact points.
 10. The case of claim 8, wherein the atleast one sensor comprises a conductive sensor configured to detect aplurality of parallel conductive traces on the dental appliance.
 11. Thecase of claim 8, wherein the digitizer platform comprises a digitizercoupled to processor to determine corresponding locations of theplurality of contact points on the tray.
 12. The case of claim 8,wherein the digitizer platform is configured to detect locations of aplurality of contact points of a polymeric shell appliance.
 13. The caseof claim 8, wherein the digitizer platform is configured to detectlocations of each of the plurality of contact points with a spatialresolution finer than about 1 mm.
 14. The case of claim 1, wherein theat least one sensor is configured to detect the deformation based ontracking three-dimensional (3D) points of the dental appliance.
 15. Thecase of claim 14, wherein the at least one sensor comprises an opticalsensor.
 16. The case of claim 15, wherein the at least one sensorcomprises a camera to generate an image of the appliance on the tray anddetect the deformation based on the image.
 17. The case of claim 15,further comprising a light emitter, and wherein the optical sensor isconfigured to detect a plurality of reflective markers on the dentalappliance.
 18. The case of claim 14, wherein the at least one sensorcomprises a magnetic sensor configured to detect a plurality of magnetson the dental appliance.
 19. The case of claim 1, further comprising atag reader for identifying the dental appliance.
 20. The case of claim19, wherein the tag reader comprises one or more of a QR code reader, abar code reader, or an RFID scanner.
 21. The case of claim 1, whereinthe case is operatively coupled to a processor configured to determine atreatment modification based on the deformation.
 22. The case of claim1, further comprising a processor operatively coupled to the at leastone sensor to determine a first shape of the appliance at a first timeand a second shape of the appliance at a second time and to detect thedeformation based on a difference between the first shape and the secondshape.
 23. The case of claim 22, wherein the processor comprises one ormore of a processor supported with the tray or a remote server.
 24. Thecase of claim 22, wherein the processor comprises instructions to detectdeformation of the appliance in response to a difference in relativelocations of a plurality of contact points.
 25. The case of claim 22,wherein the first shape comprises a first number of contact points and asecond shape comprises a second number of contact points and wherein theprocessor comprises instructions to detect deformation of the appliancein response to a difference between the first number of contact pointsand the second number of contact points.
 26. The case of claim 22,wherein the processor comprises instructions to determine an orientationof the appliance, the orientation comprises a first orientationcorresponding to an occlusal side of the appliance contacting the trayand a second orientation corresponding to a gingival side of theappliance contacting the tray.
 27. The case of claim 22, wherein theprocessor comprises instructions to determine a plurality of shapes ofthe appliance over a plurality of days, and wherein the processor isconfigured to detect deformation of the appliance.